NON-TRADITIONAL KARST TYPES IN THE SOUTHERN URALS AND CISURALS

Abstract

Despite the wide distribution of sulfate and carbonate karst in the study area, the nontraditional, rarely encountered karst types are also registered. These are clastokarst, karst of calcareous tuffs, sulfide karst, salt karst and marble karst. For each of these nontraditional types of karst, the conditions and factors of development were determined according to the karstic rock composition. Calcareous tuff karst is the least common in the study area, meanwhile clastokarst is widespread. Calcareous tuff karst is spread in the westernmost part of the Southern CisUrals, in the eastern outskirts of the Volga-Ural anteclise; and clastokarst is found in the western margin of the Yuryuzan-Sylva depression of the CisUrals marginal foredeep. Sulfide karst is developed in the plains of the Southern TransUrals within the Magnitogorsk megazone of the Ural folded system, and salt karst occurs in the flat foothills of the Southern Urals within the Belaya Megadepression and the Shikhan-Ishimbai saddle of the CisUrals marginal foredeep. It has been established that the previously identified areas of clastokarst distribution in the west of the area under consideration are not confirmed by modern and Pleistocene forms of its manifestation. The negative impact of clastokarst on economic facilities and humans is comparable to the impact of the most common and dangerous sulfate karst, and this must be taken into account when designing and constructing new buildings and engineering structures. Salt karst is manifested in artificial leaching of rock salt at a depth, such salt is necessary for the production of soda ash (JSC “Soda”); the formed voids are used as underground storage facilities for oil products (OJSC Podzemneftegaz). Calcareous tuff karst is a rare type of karst in the region under consideration, it can be observed at the complex natural monument “Shumilovsky waterfall”. Surface manifestations of sulfide karst can be a search feature of new copper-sulfide deposits. Non-traditional types of karst have both positive and negative practical implications. Karst in marble complicates the development of mineral deposits, and clastokarst complicates the economic development of the territory. Calcareous tuff karst creates unique local landforms, and sulfide karst is of practical importance in the search for new mineral deposits. On the one hand, salt karst determines the extraction of minerals deposits and contributes to the creation of useful underground storage facilities, on the other hand, it destroys them.